In the handling and the packaging of cans, it is common to use a carrier having an array of openings therein for receiving the upper ends of the cans and holding an array of cans to form a container package. Typical United States patents showing such a carrier are U.S. Pat. No. 3,874,502 and U.S. Pat. No. 4,219,117.
Such a carrier comprises a series of bands or rings which are non-circular and is applied by lateral stretching by a machine which inserts fingers into the openings to stretch the openings to a generally circular configuration and then the carrier is forced onto the upper end of the cans through the neck below the chime or bead on the cans. During the stretching and application, the bands are folded downwardly along the peripheral surface of the necks of the cans. The resultant package comprised a plurality of array of the cans surrounded by the stretched plastic rings. In such a package, the upper ends of the cans are exposed. The package offers no area wherein the carrier can be provided with printing, advertising or other indicia. Furthermore, once the cans are removed from the carrier, it is difficult if not impossible to reinsert the cans. Accordingly, the cans can not be readily handled for returning the cans for salvage or reclaiming.
In U.S. Pat. No. 4,911,290, having a common assignee with the present application, there is disclosed and claimed a container package comprises an array of cans and a carrier. The carrier includes a sheet of stiff but flexible plastic material having a plurality of openings forming an array for receiving the ends of the cans and a film of plastic material coextensive with the sheet and bonded to the periphery of the sheet so that it is flat and taut on the sheet. The cans are inserted upwardly into the openings and retained by the carrier by flexing of the periphery of each opening upwardly against the chime or bead of each can. As the cans are inserted, the film is stretched taut over the upper ends of the cans. The film is stretched substantially flat and taut from one peripheral edge to an opposite peripheral edge. The carrier thus protects the cans from contaminants. The carrier supports the array of the cans so that the upper ends of the cans are in a single plane when the package is lifted through finger openings in the film and sheet. The film and sheet define a substantially flat planar upper surface. Indicia such as printing, advertising, logos artwork and other markings are provided on the film preferably on the entire surface of the film.
The aforementioned patent describes a method of making carriers by first passing a plastic sheet through a rotary cutting die forming a strip with openings and then feeding the strip and a web of film from a roll between a heated roller that has longitudinal heated ribs that bond the film to a strip of carriers along the periphery. Transverse ribs comprise spaced ribs thereby defining separate carriers that can be severed. The transverse ribs comprise ribs of double widths so that when the carriers are subsequently cut from the web, a desired peripheral edge is provided. Roll includes arcuate bonding portions for bonding the portions from which tabs are to be formed.
The web of carriers is then passed through a die cutting roll which includes cutting edges that trim the side edges, cutting portions that trim the corners, and cutting edges that simultaneously form the fingers tabs.
By this method, a roll of carriers is provided that can then be applied to successive arrays of cans.
In utilizing such a method of making a strip of interconnected carriers, it has been found that the rate of production is limited. If the heated roller is rotated rapidly, insufficient bonding is provided between the film and the strip of sheet material. If the heated roller is rotated at a low speed, sufficient to provide proper bonding, the heat tends to melt and burn through the film so that a proper bonding is not achieved.
Accordingly, among the objectives of the present invention are to provide a carrier which can be made rapidly at high speeds without melting and burning through the film; which produces a proper bond of the film to the sheet strip; and which is produced by method that obviates the aforementioned problems.
In accordance with the invention, a carrier for a container package holding an array of cans each of which has an annular bead on the upper end thereof comprises a sheet of flexible plastic material having a plurality of openings forming an array for receiving the ends of the cans and at least one film of plastic material coextensive with the sheet and bonded to the periphery of the sheet. The sheet is made as a coextruded sheet comprising a first layer relatively thick and a second relatively thin layer adjacent the film. The second layer has a melting point lower than that of the first layer or the film and facilitates the bonding of the film to the sheet by heat. In a modified form two layers of film are bonded to the sheet.